# Math Help - Independant and Disjoint Events

1. ## Independant and Disjoint Events

I have managed to figure out the first part, however the second part stumps me. Could someone walk me through this?

2. Originally Posted by Sakurazaki
I have managed to figure out the first part, however the second part stumps me. Could someone walk me through this?

You know that $\Pr(E \cup F) = \Pr(E) + \Pr(F) - \Pr(E \cap F)$ .... (1)

And if E and F are independent you know that $\Pr(E \cap F) = \Pr(E) \cdot \Pr(F)$ .... (2)

Substitute (2) into (1), then substitute the given data and solve for Pr(F).